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07:54
Fluorescence Recovery after Merging a Droplet to Measure the Two-dimensional Diffusion of a Phospholipid Monolayer
Published on: October 15, 2015
Effect of cholesterol on diffusion in surfactant bilayers
Thorsten Pieper1, Svetlana Markova, Masataka Kinjo
1University of Dortmund, Exp. Physics III, Dortmund D-44221, Germany. thorsten.pieper@gmx.de
The Journal of Chemical Physics
|November 6, 2007
Summary
Cholesterol influences biological membrane microdomains, affecting molecular mobility. This study in a surfactant model shows cholesterol addition significantly reduces molecular diffusion even at low concentrations.
Area of Science:
- Biophysics
- Materials Science
- Physical Chemistry
Background:
- Biological membranes feature lipid bilayers with distinct liquid-ordered and liquid-disordered phases.
- Cholesterol is thought to regulate microdomain size, impacting membrane mobility and permeability.
Purpose of the Study:
- Investigate cholesterol's effect on molecular mobility in a model membrane system.
- Quantify the relationship between cholesterol concentration and diffusion in a nonionic surfactant lamellar phase.
Main Methods:
- Utilized a model system of nonionic surfactant C(12)E(5) and water in a lamellar phase.
- Employed fluorescence correlation spectroscopy to measure the diffusion of rhodamine B probe molecules.
- Varied surfactant-to-water ratios and systematically added cholesterol.
Main Results:
- Observed a reduction in the diffusion coefficient of probe molecules with increasing cholesterol content.
- Detected a significant decrease in molecular mobility at as low as 8 mol % cholesterol.
- Demonstrated cholesterol's impact on molecular diffusion in this model system.
Conclusions:
- Cholesterol addition demonstrably affects molecular mobility in C(12)E(5)/water lamellar phases.
- Even small amounts of cholesterol can alter membrane dynamics.
- The findings support cholesterol's role in modulating membrane properties.
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